Passive Sampler

What is passive sampling of SARS-CoV-2 in wastewater?

Passive sampling involves the deployment of a device in a waterbody for a known time period, allowing for pollutants in the water to interact with the device. This interaction could include the association of a pollutant with a particular medium or substance or induces a chemical reaction within the device. At the end of the deployment, the passive sampler is analysed through visual inspection or via advanced laboratory analytical methods. A notable advantage of passive sampling in water systems is that the deployment is easy (i.e. no specialised skills required), rapid and usually does not require confined space entry permits. Furthermore, the continuous exposure of the passive sampler to the water column reduces the sampling errors that exist when taking discrete water samples. Consequently, passive sampling has had a significant uptake in freshwater resource settings, especially in the field of water chemistry, where both time- and flow-based passive sampling techniques have been validated.

The application of passive sampling in water and wastewater microbiology has not received much research attention. Some studies have used glass bead passive samplers, one to characterise colonising biofilms in groundwater and the other to monitor for pathogens in wastewater. Some have trialled several passive samplers, including Zetapor membranes, nylon materials, low-density polyethylene and polyvinylidene difluoride for the detection of herpesviruses and noroviruses in seawater. But most studies monitored pathogens in wastewater systems using the Moore’s swab, which is a piece of medical gauze that is placed in the wastewater for 1 to 7 days and is attached to a string for retrieval. Slight modifications to the Moore’s swab have been adopted to monitor for polioviruses in wastewater. Recently, researchers have revived the use of passive samplers for the detection of SARS-CoV-2 in wastewater. If you are interested in these publications, please navigate to https://www.passives4covid.org/publications.php.

Publication on our passive samplers

We now have our paper published online in Environmental Science and Technology: https://pubs.acs.org/doi/10.1021/acs.est.1c01530

Torpedo Passive Sampler Housing Units

We have developed some neat little units that can house many types of passive sampling materials - they are designed in a torpedo shape to reduce clogging and fouling during deployment in wastewater sewers. You can either place an order for some to be delivered to your work or you can download the 3D print files - for free!

ORDER YOURS TODAY: Please use this form to order some 3D printed torpedoes - these will be delivered to your door, fully assembled ready to deploy: https://forms.gle/ntPJj4iQSzG7cryX7

DOWNLOAD DESIGN FOR FREE: If you have access to your own 3D printer, you can download and use as you wish! To download, please fill out the following google form (we do not collect any personal information here, so please never enter passwords or anything like this): https://forms.gle/31XgRkGvfVc5fKvW7
Smaller Torpedos - PENSIVES: We have developed some nice little new passive sampling housings/units, small enough to fit into individual allotment connections. Want to download these little beauties? Check out this link: https://doi.org/10.17632/566rkkxcf9.1 You can also order these to your door - just use the same form as above and place "PENSIVE" in the comment box.

Deployment Procedure

This video demonstrates the appropriate method of deploying a passive sampler into the sewer network. Please note, in this case the field worker checks for dangerous gases first and also collects a grab/spot sample.

Dismantling Procedure

This video demonstrates the appropriate process for dismantling of the passives sampler.